27890861 has 4 divisors (see below), whose sum is σ = 27927900. Its totient is φ = 27853824.

The previous prime is 27890813. The next prime is 27890867. The reversal of 27890861 is 16809872.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21104836 + 6786025 = 4594^2 + 2605^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27890861 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27890867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17366 + ... + 18903.

It is an arithmetic number, because the mean of its divisors is an integer number (6981975).

Almost surely, 2^27890861 is an apocalyptic number.

It is an amenable number.

27890861 is a deficient number, since it is larger than the sum of its proper divisors (37039).

27890861 is an equidigital number, since it uses as much as digits as its factorization.

27890861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37038.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 27890861 is about 5281.1798871086. The cubic root of 27890861 is about 303.2638474121.

The spelling of 27890861 in words is "twenty-seven million, eight hundred ninety thousand, eight hundred sixty-one".